The present invention relates to a cushioning structure suitable for use as a shoe sole or insole but also as an insert structure for cushioning any object that requires cushioning properties such as a seat covering, a bicycle seat or a mattress. It also relates to a method of making such cushioning structure.
Commonly used in prior art for cushioning a car seat, a chair, a mattress or any other object devised to be in contact with a human or animal body part that requires cushioning properties, there is the traditional foam pad which consists of a uniform thickness pad having a uniform density throughout and deprived of any particular aeration system.
The prior art also teaches a number of structures used as shoe soles and consisting of a central layer of flexible material incorporating a plurality of asperities distributed thereon and acting as individual suspension. Examples of such prior art shoe soles are given in U.S. Pat. Nos. 4,345,387; 4,541,185; 4,733,483; 4,831,749 and 4,896,441.
Also disclosed in prior art, there are different types of soles incorporating pumping means for aerating the foot during the walking movement of the user. Examples of such prior art shoe soles are given in U.S. Pat. Nos. 4,215,492; 4,223,455; 4,224,746; 4,468,869; 4,776,109; 4,813,160; 4,831,749 and 5,619,809.
There is also a number of orthopedic innersoles disclosed in prior art which provide an adequate conformation to the particular shape of the bottom of the foot in order for example to correct eventual defects to the user""s foot. Such innersoles are disclosed in U.S. Pat. Nos. 4,598,484; 4,733,483 and 4,896,441.
Although many developments have been made, especially in the shoe industry, for providing comfortable soles, there is still a need for a cushioning structure devised to be in contact with a human or animal body part and that optimally suits the physical characteristics of the body part. There is also a need for a cushioning structure for use in contact with a body part that could provide in the same time a real comfort adapted to the physical characteristics of the user and an efficient aeration system. Also needed is such a structure for cushioning any object that requires cushioning properties such as a seat covering, a bicycle seat, a shoe sole or a mattress.
Therefore an object of the present invention is to propose a cushioning structure for use in contact with a human or animal body part and that optimally suits the physical characteristics of the body part.
Another object of the present invention is to propose a method of making such a cushioning structure.
In accordance with the present invention, one object is achieved with a cushioning structure for use in contact with a human or animal body part, the body part being characterised by a pressure map. The cushioning structure comprises a central layer of a rubber-like thermoplastic material having an upper surface and a bottom surface. The upper surface is devised to be in contact with the body part and preferably has a shape relief conforming a specific shape relief of the body part.
The structure further comprises a layout of space-apart anatomical pressure-receiving fingers made integrally with the central layer and protruding from at least one of the upper surface and bottom surface. Each of the pressure receiving fingers has a predetermined height and diameter. The structure is characterised in that the layout, the height and the diameter of the pressure-receiving fingers is determined in function of the physical characteristics of the rubber-like thermoplastic material and of the specific pressure map of the body part, whereby the overall pressure-receiving fingers suits the specific pressure map of the body part.
The layout, the height and the diameter of the pressure-receiving fingers are determined by computer modelling.
Also preferably, the cushioning structure further comprises a layout of air holes distributed between the pressure-receiving fingers and extending across the central layer from the upper surface to the bottom surface.
In a preferred embodiment of the present invention, the pressure-receiving fingers protrude only from the bottom surface and the structure further comprises on the upper surface thereof a plurality of massaging buttons to massage the body part.
Also in accordance with the present invention, another object is achieved with a method of making a cushioning structure as defined hereinbefore comprising the steps of:
a) providing the pressure map of the body part;
b) determining an implantation map of the anatomical pressure receiving fingers in function of the pressure map, the implantation map giving the layout, the height and the diameter of each pressure receiving finger;
c) providing an injection mould conforming with the implantation map obtained in step b) and preferably with the shape relief map of the body part; and
d) moulding by injection the cushioning structure in the mould obtained in step c).
The implantation map is determined by computer modelling.
The cushioning structure according to the invention is intended to be used as an insert structure for cushioning any object that requires cushioning properties such as a shoe sole or insole, a seat covering, a bicycle seat or a mattress.
An advantage of a cushioning structure according to the present invention over the prior art cushioning structures is that it is optimally comfortable for the user as it is obtained by taking into account the specific pressure map of the body part to which it is intended to be in contact with. Another advantage of the present invention is that it proposes a simple method to manufacture at once many different types of cushioning structures suiting different purposes.
As stated previously, the shape, size, height and composition of the anatomical pressure-receiving fingers may vary and the choice of these characteristics is determined according to the specific pressure points and the density required at specific locations of the structure in use. Of course, the thickness of the central layer can also be adjusted. For example, if the cushioning structure is used in the making of a bicycle seat, the density may be adjusted for providing an ergonomic and comfortable seat. Such cushioning structure could also be used as a shoe sole, the central layer and pressure-receiving fingers having a variable thickness providing an orthopedic profile for the shoe sole.